U.S. patent number 11,319,764 [Application Number 15/782,960] was granted by the patent office on 2022-05-03 for downhole pulsing-shock reach extender system.
This patent grant is currently assigned to PETROSTAR SERVICES, LLC. The grantee listed for this patent is PETROSTAR SERVICES, LLC. Invention is credited to Christopher Gasser, Brady Guilbeaux, Richard Messa, Ashley Rochon.
United States Patent |
11,319,764 |
Messa , et al. |
May 3, 2022 |
Downhole pulsing-shock reach extender system
Abstract
A downhole pulsing-shock reach extender apparatus for overcoming
static friction resistance in coiled-tubing drilling-fluid-pressure
driven downhole operations, generating pulsed hydraulic shocks at
the workstring by creating a fluid-hammer condition by repeated
sudden opening and closing of a valve controlling a diverted
portion of the flow of drilling fluid, while maintaining a constant
flow of a portion of drilling fluid sufficient to operate and
prevent damage to other components of the workstring, thereby
extending the depth limit of downhole operations.
Inventors: |
Messa; Richard (Broussard,
LA), Gasser; Christopher (Houston, TX), Guilbeaux;
Brady (Maurice, LA), Rochon; Ashley (New Iberia,
LA) |
Applicant: |
Name |
City |
State |
Country |
Type |
PETROSTAR SERVICES, LLC |
San Antonio |
TX |
US |
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Assignee: |
PETROSTAR SERVICES, LLC (San
Antonio, TX)
|
Family
ID: |
1000006277931 |
Appl.
No.: |
15/782,960 |
Filed: |
October 13, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180179841 A1 |
Jun 28, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15428792 |
Feb 9, 2017 |
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15392846 |
Dec 28, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B
28/00 (20130101); E21B 34/14 (20130101); E21B
7/046 (20130101); E21B 4/02 (20130101) |
Current International
Class: |
E21B
28/00 (20060101); E21B 7/04 (20060101); E21B
4/02 (20060101); E21B 34/14 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sebesta; Christopher J
Assistant Examiner: Patel; Neel Girish
Attorney, Agent or Firm: Mueller; Jason P. FisherBroyles,
LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my co-pending
application Ser. No. 15/428,792, filed Feb. 9, 2017 for a "Downhole
Fluid-Pressure Safety Bypass Apparatus," which is a
continuation-in-part of my application Ser. No. 15/392,846, filed
Dec. 28, 2016 for a "Downhole Pulsing Shock-Reach Extender System,"
currently pending, the full disclosures of which are incorporated
by reference herein and priority of which is hereby claimed.
Claims
We claim:
1. A downhole pulsing-shock reach extender comprising: (i) a
tubular tool housing adapted to being mounted in a workstring, and
having, an up-hole end and a downhole end; (ii) a top sub adapted
to connect the up-hole end of the tool housing to the workstring,
and having a central axial opening; (iii) a bottom sub adapted to
connect the downhole end of the tool housing to the workstring, and
having a central axial opening; (iv) a fluid motor axially mounted
inside the tool housing forming a perimeter fluid channel between
the fluid motor and an interior wall of the tool housing, wherein
the fluid motor has a central axial opening, wherein the fluid
motor is adapted to rotate in response to a flow of drilling fluid;
(v) a changeable center orifice mounted within the top sub, in line
with the central axial opening of the fluid motor; (vi) at least
one changeable bypass orifice mounted within the top sub, in line
with the perimeter fluid channel; (vii) a foot-valve bottom plate
with a central axial opening in fluid communication with the
central axial opening of the fluid motor, wherein the foot-valve
bottom plate is fixedly mounted inside the bottom sub, wherein the
foot-valve bottom plate has a circular up-hole surface with at
least one void-extending from an outer circumferential edge of the
foot-valve bottom plate toward a center of the foot-valve bottom
plate and in line with the perimeter fluid channel; and (viii) a
foot-valve top plate rotatingly mounted inside the bottom sub
immediately up-hole of the foot-valve bottom plate, wherein the
foot-valve top plate is connected to and rotates with the fluid
motor, wherein the foot-valve top plate has a central axial opening
in fluid communication with the central axial opening of the fluid
motor, wherein the central axial openings of the foot-valve bottom
plate and the foot valve top plate define a constant fluid flow
path from the central axial opening of the fluid motor through the
foot-valve plates, and wherein the foot-valve top plate has a
shutter member having a downhole surface with a radius as large or
larger than a radius of the foot-valve bottom plate, wherein the
shutter member is adapted to alternately block and not block the at
least one void in the up-hole surface of the foot-valve bottom
plate, during rotation of the foot-valve top plate wherein the void
of the foot-valve bottom plate defines a pulsating fluid flow path
from the perimeter fluid channel through the foot-valve plates,
wherein the constant fluid flow path and pulsating fluid flow path
are fluidly isolated from one another through the foot-valve
plates.
2. The downhole pulsing-shock reach extender of claim 1, wherein
said tool housing, top sub, and bottom sub are made of steel.
3. The downhole pulsing-shock reach extender of claim 1, wherein
said changeable center orifice and changeable bypass orifices are
made of steel.
4. The downhole pulsing-shock reach extender of claim 1, wherein
said foot-valve bottom plate and foot-valve top plate are made of
steel.
5. The downhole pulsing-shock reach extender of claim 1, wherein
said changeable bypass orifices are configured to divert from 10%
to 33%, inclusive, of the volume of the drilling fluid flowing into
an up-hole end of the top sub.
6. The downhole pulsing-shock reach extender of claim 1, wherein
said changeable bypass orifices are configured to divert not
greater than half of the volume of the drilling fluid flowing into
an up-hole end of the top sub.
7. The apparatus of claim 1, wherein the shutter member has an
outer curvature that matches an outer curvature of the foot-valve
bottom plate.
8. The apparatus of claim 1, wherein a surface area of the downhole
surface of the shutter member is greater than a cross-sectional
area of the void in the circular up-hole surface of the foot-valve
bottom plate.
9. A method, comprising: inserting a workstring into a hole;
pumping drilling fluid down the workstring, wherein the workstring
comprises a downhole pulsing-shock reach extender comprising: (i) a
tubular tool housing adapted to being mounted in the workstring,
having, in use, an up-hole end and a downhole end; (ii) a top sub
adapted to connect the up-hole end of the tool housing to the
coiled-tubing workstring, the top sub having a central axial
opening allowing a flow of the drilling fluid; (iii) a bottom sub
adapted to connect the downhole end of the tool housing to the
coiled-tubing workstring, the bottom sub having a central axial
opening allowing a flow of the drilling fluid; (iv) a fluid motor
axially mounted inside the tool housing, forming a perimeter fluid
channel between the fluid motor and an interior wall of the tool
housing, the fluid motor having a central axial opening for the
flow of the drilling fluid, the fluid motor configured to rotate in
response to a flow of the drilling fluid; (v) a changeable center
orifice mounted within the top sub, in line with the central axial
opening of the fluid motor; (vi) at least one changeable bypass
orifice mounted within the top sub, in line with the perimeter
fluid channel between the tool housing and the fluid motor; (vii) a
foot-valve bottom plate with a central axial opening in fluid
communication with the central axial opening of the fluid motor,
fixedly mounted inside the bottom sub, the foot-valve bottom plate
having a circular up-hole surface with at least one void extending
from an outer circumferential edge of the foot-valve bottom plate
toward a center thereof and in line with the perimeter fluid
channel; and (viii) a foot-valve top plate rotatingly mounted
inside the bottom sub immediately up-hole of the foot-valve bottom
plate, the foot-valve top plate connected to the fluid motor to
rotate with the fluid motor, having a central axial opening in
fluid communication with the central axial opening of the fluid
motor, wherein the central axial openings of the foot-valve bottom
plate and the foot valve top plate define a constant fluid flow
path from the central axial opening of the fluid motor through the
foot-valve plates, and having a shutter member having a downhole
surface with a radius as large or larger than a radius of the
foot-valve bottom plate, wherein the shutter member is adapted to
block the at least one void in the up-hole surface of the
foot-valve bottom plate and to not block the at least one void in
the up-hole surface of the foot-valve bottom plate, in an
alternating cycle, during rotation of the foot-valve top plate,
wherein the void of the foot-valve bottom plate defines a pulsating
fluid flow path from the perimeter fluid channel through the
foot-valve plates, wherein the constant fluid flow path and
pulsating fluid flow path are fluidly isolated from one another
through the foot-valve plates.
10. The method of claim 9, further comprising: attaching a downhole
tool on the workstring downhole from the downhole pulsing-shock
reach extender.
11. The method of claim 9, further comprising: inserting the at
least one lock pin into the bottom sub and into the foot-valve
bottom plate.
12. A method for assembling a downhole pulsing-shock reach
extender, the method comprising: (i) providing a tubular tool
housing adapted to being mounted in a coiled-tubing workstring, the
tool housing having a first end and a second end; (ii) connecting a
top sub to the first end of the tool housing; (iii) mounting a
fluid motor inside the tool housing such that a perimeter fluid
channel is formed between the fluid motor and an interior wall of
the tool housing and a central axial opening extends through the
fluid motor; (iv) providing a bottom sub adapted to connect to the
second end of the tool housing; (v) fixedly mounting a foot-valve
bottom plate inside the bottom sub, the foot-valve bottom plate
having a central axial opening and a circular surface with at least
one void extending from an outer circumferential edge of the
foot-valve bottom plate toward a center thereof, wherein the void
is in line with the perimeter fluid channel; (vi) inserting at
least one lock pin into the bottom sub and into the foot-valve
bottom plate; (vii) rotatingly mounting a foot-valve top plate
inside the bottom sub adjacent to the foot-valve bottom plate, the
foot-valve top plate having a central axial opening and having a
shutter member having a surface with a radius as large or larger
than a radius of the foot-valve bottom plate, wherein the shutter
member is adapted to block the at least one void in the surface of
the foot-valve bottom plate and to not block the at least one void
in the surface of the foot-valve bottom plate, in an alternating
cycle, during rotation of the foot-valve top plate; (viii)
connecting the foot-valve top plate with the fluid motor such that
the central axial opening of the foot-valve top plate is in fluid
communication with the central axial opening of the fluid motor;
(ix) connecting the bottom sub with the tool housing, such that the
central axial opening of the foot-valve bottom plate is in fluid
communication with the central axial opening of the fluid motor
wherein the central axial openings of the foot-valve bottom plate
and the foot valve top plate define a constant fluid flow path from
the central axial opening of the fluid motor through the foot-valve
plates and wherein the void of the foot-valve bottom plate defines
a pulsating fluid flow path from the perimeter fluid channel
through the foot-valve plates, wherein the constant fluid flow path
and pulsating fluid flow path are fluidly isolated from one another
through the foot-valve plates; (x) installing at least one
changeable bypass orifice within the top sub, in line with the
perimeter fluid channel between the tool housing and the fluid
motor; and (xi) installing a changeable center orifice within the
top sub, in line with the central axial opening of the fluid motor.
Description
BACKGROUND
This invention is a downhole pulsing-shock reach extender apparatus
for overcoming static friction resistance in coiled-tubing
drilling-fluid-pressure driven downhole operations.
Drilling, in its broad sense, includes not only the initial
drilling of a hole, but many subsequent trips down the hole for
workover and inspection. Where older methods of drilling use
sections of rigid pipe threaded together, coiled-tubing drilling
uses a somewhat flexible, continuous tube that can be spooled when
not in use. The power for rigid-pipe drilling is applied at the
turntable on the rig; the power for coiled-tubing drilling, in
contrast, is applied at or near the drill bit or workstring, by
converting pressure applied to drilling fluid or drilling mud at
the wellhead, transmitted down the great length of coiled tubing,
and converted to rotational force by a fluid motor or mud motor.
This technique allows for directional drilling, including
horizontal drilling, and accordingly includes changes of direction
during drilling. In coiled-tubing operations, the depth of a hole
might include substantial portions of horizontal or near-horizontal
runs.
In rigid-pipe drilling, the function of drilling fluid or drilling
mud is to provide lubrication, flushing of tailings, and counter
pressure down the hole. Coiled-tubing drilling uses the drilling
fluid or mud for an additional purpose of transmitting power or
force to the workstring, which is thousands of feet distant,
underground.
Coiled-tubing operations will always encounter increased resistance
at increasing depths. Although the coiled tubing is straightened
before insertion, there is a likelihood of some residual shape
memory to nudge the deployed tubing away from perfectly straight,
given its original coiled shape. Directional drilling usually
involves changes of direction, and each change of direction
provides a point of increased drag while diminishing any benefit
from downward, insertion force applied at the wellhead. Because
there is likely to be at least some drag all along the surface of
the deployed tubing, a longer, or deeper, run will encounter,
increasing total drag. Very deep coiled-tubing operations therefore
encounter increased drag, or static friction, which eventually
cannot be overcome. This limits the depths attainable by the
operation.
It is known that a given amount of force, when applied gradually or
constantly, will not be sufficient to overcome static friction, but
that the same total amount of force, when applied as pulses, will
overcome the static friction. A nail that cannot be pressed into a
block of wood can be hammered into it. The pulse of force is able
to work as intended for a brief time before being dispersed. But
any pulse of more pressure applied at the wellhead will dissipate,
and will not be felt at the distant workstring. All changes of
pressure at the workstring will necessarily be gradual, buffered
changes. If too great an amount of mud pressure is forced down the
coiled tubing, it will damage or destroy the mud motor.
The present art does not provide an effective way of generating
pulses of hydraulic shock within the workstring itself, while
avoiding the application of too much pressure within the long run
of coiled tubing and at the workstring, and while avoiding damage
to mud motors and other components of the workstring.
U.S. Publ. No. 2016/0312559 was published on Oct. 27, 2016 by
inventors Ilia Gotlib et al. and assignee Sclumberger Technology
Corp., and covers a "Pressure Pulse Reach Extension Technique." The
pressure pulse tool and technique allows for a reciprocating piston
at a frequency independent of a flow rate of the fluid that powers
the reciprocating. The architecture of the tool and techniques
employed may take advantage of a Coanda or other implement to
alternatingly divert fluid flow between pathways in communication
with the piston in order to attain the reciprocation. Frequency of
reciprocation may be between about 1 Hz and about 200 Hz, or other
suitably tunable ranges. Once more, the frequency may be enhanced
through periodic exposure to annular pressure. Extended reach
through use of such a pressure pulse tool and technique may exceed
about 2,000 feet.
U.S. Publ. No. 2016/0130938 was published on May 12, 2016 by
inventor Jack J. Koll and assignee Tempress Technologies, Inc., and
discloses "Seismic While Drilling System and Methods." A bottom
hole assembly is configured with a drill bit section connected to a
pulse generation section. The pulse generation section includes a
relatively long external housing, a particular housing length being
selected for the particular drilling location. The long external
housing is positioned closely adjacent to the borehole sidewalls to
thereby create a high-speed flow course between the external walls
of the housing and the borehole sidewalls. The long external
housing includes a valve cartridge assembly and optionally a shock
sub decoupler. While in operation, the valve cartridge assembly
continuously cycles and uses downhole pressure to thereby generate
seismic signal pulses that propagate to geophones or other similar
sensors on the surface. The amount of bypass allowed through the
valve assembly is selectable in combination with the long external
housing length and width to achieve the desired pulse
characteristics. The bottom hole assembly optionally includes an
acoustic baffle to attenuate wave propagation going up the drill
string.
U.S. Publ. No. 2014/0048283, published by Brian Mohon et al. on
Feb. 20, 2014, covers a "Pressure Pulse Well Tool." The disclosure
of the Mohen publication is directed to a pressure pulse well tool,
which may include an upper valve assembly configured to move
between a start position and a stop position in a housing. The
pressure pulse well tool may also include an activation valve
subassembly disposed within the upper valve assembly. The
activation valve subassembly may be configured to restrict a fluid
flow through the upper valve assembly and increase a fluid pressure
across the upper valve assembly. The pressure pulse well tool may
further include a lower valve assembly disposed inside the housing
and configured to receive the fluid flow from the upper valve
assembly. The lower valve assembly may be configured to separate
from the upper valve assembly after the upper valve assembly
reaches the stop position, causing the fluid flow to pass through
the lower valve assembly and to decrease the fluid pressure across
the upper valve assembly.
U.S. Pat. No. 8,082,941 issued Dec. 27, 2011 to Alessandro O.
Caccialupi et al. for a "Reverse Action Flow Activated Shut-Off
Valve." The Caccialupi flow-activated valve includes an outer body
and a piston disposed in an inner cavity of the outer body. The
flow-activated valve also includes one or more fluid passage exits
in the outer body and one or more piston fluid passages in the
piston. The one or more fluid passage exits and the one or more
piston fluid passages allow fluid flow out of the valve. The
flow-activated valve also includes a flow restriction member
disposed in a piston inner cavity. In addition, the flow-activated
valve includes a shear member disposed in the outer body, and a
bias member disposed in an inner cavity of the outer body. The
flow-activated valve further includes a position control member
disposed in the piston and a sealing member.
U.S. Pat. No. 7,343,982 issued to Phil Mock et al. on Mar. 18, 2008
for a "Tractor with Improved Valve System." The system covers a
hydraulically powered tractor adapted for advancement through a
borehole, and includes an elongated body, aft and forward gripper
assemblies, and a valve control assembly housed within the
elongated body. The aft and forward gripper assemblies are adapted
for selective engagement with the inner surface of the borehole.
The valve control assembly includes a gripper control valve for
directing pressurized fluid to the aft and forward gripper
assemblies. The valve control assembly also includes a propulsion
control valve for directing fluid to an aft or forward power
chamber for advancing the body relative to the actuated gripper
assembly. Aft and forward mechanically actuated valves may be
provided for controlling the position of the gripper control valve
by detective and signaling when the body has completed an
advancement stroke relative to an actuated gripper assembly. Aft
and forward sequence valves may be provided for controlling the
propulsion control valve by detecting when the gripper assemblies
become fully actuated. A pressure relief valve is preferably
provided along an input supply line for liming the pressure of the
fluid entering the valve control assembly.
U.S. Pat. No. 2,576,923, issued on Dec. 4, 1951 to Clarence J.
Coberly for a "Fluid Operated Pump with Shock Absorber," relates in
general to equipment for pumping fluid from wells and, more
particularly, to an apparatus which includes a reciprocating pump
of the fluid-operated type. A primary object of the invention is to
provide an apparatus having cushioning means associated therewith
for absorbing any fluid pressure variations which may impose
hydraulic shock loads on the system. The fluid operated pumping
unit includes a combination of (1) a source of a first fluid at a
substantially constant pressure level; (2) a receiver for a second
fluid to be pumped; (3) a pump adapted to be operating by the first
fluid to pump the second fluid; (4) a shock absorber connected to
the pump and having movable fluid separating means within it; (5)
means for a first passage communicating between the source and the
shock absorber for admitting the first fluid into the shock
absorber on one side of the fluid separating means; (6) and a
second passage means communicating between the receiver and the
shock absorber for admitting the second fluid into the shock
absorber on the opposite side of the fluid separating means.
U.S. Pat. No. 8,967,268, issued to Larry J. Urban et al. on Mar. 3,
2015, covers "Setting Subterranean Tools with Flow Generated Shock
Wave." In the Urban patent, a circulation sub is provided that has
a ball seat and a circulation port that is closed when a ball is
landed on the seat. An axial passage directs the pressure surge
created with the landing of the ball on the seat to the port with
the actuation piston for the tool. The surge in pressure operations
the actuation piston to set the tool, which is preferably a packer.
Raising the circulation rate through a constriction in a
circulation sub breaks a shear device and allows the restriction to
shift to cover a circulation port. The pressure surge that ensues
continues through the restriction to the actuating piston for the
tool to set the tool. The Urban patent was assigned to Baker Hughes
Inc. on Nov. 30, 2011.
U.S. Pat. No. 8,939,217, issued Jan. 27, 2015 to inventor Jack J.
Koll and assignee Tempress Technologies, Inc., covers a "Hydraulic
Pulse Valve with Improved Pulse Control." Hydraulic pulses are
produced each time that a pulse valve interrupts the flow of a
pressurized fluid through a conduit. The pulse valve includes an
elongated housing having an inlet configured to couple the conduit
to receive the pressurized fluid, and an outlet configured to
couple to one or more tools. In the housing, a valve assembly
includes a poppet reciprocating between open and closed positions,
and a poppet seat, in which the poppet closes to at least partially
block the flow of pressurized fluid through the valve. A pilot
within the poppet moves between disparate positions to modify fluid
paths within the valve. When the valve is open, a relatively lower
pressure is produced by a Venturi effect as the fluid flows through
a throat in the poppet seat, to provide a differential pressure
used to move the pilot and poppet. An optional bypass reduces the
pulse amplitude.
SUMMARY OF THE INVENTION
The present invention provides a downhole pulsing-shock reach
extender apparatus for overcoming static friction resistance in
coiled-tubing drilling-fluid-pressure driven downhole operations,
generating pulsed hydraulic shocks at the workstring by creating a
fluid-hammer condition by repeated sudden opening and closing of a
valve, controlling a diverted portion of the flow of drilling fluid
while maintaining a constant flow of a portion of drilling fluid
sufficient to operate and prevent damage to other components of the
workstring, thereby extending the depth limit of downhole
operations.
BRIEF DESCRIPTION OF DRAWINGS
Reference will now be made to the drawings, wherein like parts are
designated by like numerals, and wherein:
FIG. 1 is a schematic view illustrating the downhole pulsing-shock
reach extender of the invention in use;
FIG. 2 is an exploded view of the downhole pulsing-shock reach
extender of the invention;
FIG. 3 is two top cutaway views of the downhole pulsing-shock reach
extender of the invention with the valve opened and closed;
FIG. 4 is two perspective cutaway detail views of a portion of the
downhole pulsing-shock reach extender of the invention with the
valve opened and closed;
FIG. 5 is a perspective detail view of the downhole portion of the
downhole pulsing-shock reach extender of the invention;
FIG. 6 is six sectional views of the downhole portion of the
downhole pulsing-shock reach extender of the invention in use;
FIG. 7 is two sectional views of the up-hole portion of the
downhole pulsing-shock reach extender of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the downhole pulsing-shock reach extender 10
of the invention is shown schematically, in use in coiled-tubing,
directional drilling, downhole operations.
The downhole pulsing-shock reach extender 10 assists significantly
in overcoming the static friction encountered in deep
directional-drilling downhole coiled-tubing operations by
generating pulsed hydraulic shocks, which are a pulsation of energy
at the workstring, by creating a fluid-hammer condition using an
essentially constant or slowly changing normal drilling-fluid
pressure which will not damage other components of the workstring,
thereby extending the depth limit of downhole operations.
The downhole pulsing-shock reach extender 10 generates a force,
during a small window of time, that is able to work as intended
before being dispersed, in a continuing cycle. No pulsation from
the wellhead can effectively reach the workstring. Moreover, the
application of an extreme amount of pressure will only damage or
destroy the workstring's components. The downhole pulsing-shock
reach extender 10 generates the needed pulsing shocks at the needed
locus of the workstring, using the available, normal mud pressure,
and without exposing the other components of the workstring to
damage or destruction from excessive pressures.
The hammer or shock set up in the drilling mud inside the downhole
pulsing-shock reach extender 10 will impart a jerk, also known as
jolt, surge, or lurch, to the body of the extender and to the other
elements of the workstring, causing a mechanical or physical shock
that assists the workstring in overcoming static friction. The
downhole pulsing-shock reach extender 10 is designed to be made up
above the mud motor. It interrupts the flow of drilling fluid
utilizing a fluid-hammer effect, and causes the workstring to
expand and contract above the tool. This allows the tool to "walk,"
and to give extended reach to the workstring.
Referring additionally to FIG. 5 & FIG. 6, the method used to
interrupt the flow in this tool is a foot valve housed in a bottom
sub 8, at the downhole or bottom end of the downhole pulsing-shock
reach extender 10, having a set of plates, one stationary and one
rotating, with a fluid path through them, all driven by a
fluid-actuated motor. As can be seen in particular detail in FIG.
5, the foot-valve top plate 6 comprises an arcuate shutter member
16 having an outer curvature 17 that matches an outer curvature 18
of the foot-valve bottom plate 7. The foot-valve bottom plate 7 has
a cutout 19 that extends from an outer curved edge 20 of the
foot-valve bottom plate 7 towards a center thereof. As shown in
FIGS. 5 and 6, the cutout 19 is formed off center. When the cutout
19 is covered by the shutter member 16, no fluid flow is allowed
through the off-center cutout 19. As can be seen in FIG. 6, the
surface area of the shutter member 16 is greater than the opening
formed by the cutout 19. As the foot-valve top plate 6 turns in
relation to the stationary foot-valve bottom plate 7, the fluid
path lines up temporarily in an open position, opening the cutout
19, and allowing fluid to flow, before being interrupted as the
plate continues to turn, increasing the pressure and causing the
fluid hammer. As schematically shown in FIG. 6, when the foot-valve
bottom plate 6 is turned, the shutter member 16 gradually covers
the cutout 19 until the entire passage formed by the cutout 19 is
blocked, the off-center fluid pass is closed off, and no fluid
flows through the foot-valve bottom plate 7.
Referring now to FIG. 2, the downhole pulsing-shock reach extender
10 provides a tool housing 4 enclosing a fluid motor 5. The fluid
motor 5, or mud motor, converts some of the energy from pressurized
drilling fluid or drilling mud flowing through it into rotational
energy or torque to rotate the foot-valve top plate 6. The fluid
motor 5 has a central axial opening forming a tube that conveys
drilling fluid or drilling mud from the up-hole or top end to the
downhole or bottom end, and then the drilling fluid flows on into
the downhole workstring components such as the drilling bit. The
outer circumference of the fluid motor 5 is smaller than the inner
circumference of the tool housing 4 so that a perimeter fluid
channel is formed, allowing the flow of drilling fluid around the
fluid motor 5 instead of through it. One advantage of this
perimeter fluid channel is that it provides for improved cooling
and lubrication of the fluid motor 5 in relation to a fluid motor
that is directly exposed to the well bore.
On the downhole end of the downhole pulsing-shock reach extender 10
is attached the bottom sub 8 housing the foot-valve top plate 6 and
foot-valve bottom plate 7. In a preferred embodiment, a lock pin 9
or lock pins are used to reinforce the screw-thread attachment of
the bottom sub 8 to the tool housing 4 against the rotational force
acting to unscrew it, and therefore also maintaining the relative
orientation of the opening in the foot-valve bottom plate 7. Both
the foot-valve top plate 6 and the foot-valve bottom plate 7 have
central axial openings corresponding to the central axial opening
of the fluid motor 5, allowing the constant, unimpeded flow of
drilling fluid from the drilling motor 5, through the bottom sub 8,
and on to the downhole components of the workstring.
Referring additionally to FIG. 7, on the up-hole end of the
downhole pulsing-shock reach extender 10 is attached the top sub 1,
housing a center orifice 2 in alignment with the central axial
opening of the fluid motor 5, and several bypass orifices 3 arrayed
in alignment with the perimeter fluid channel around the fluid
motor 5. By manipulating the opening size of the center orifice 2
and the number of, and opening sizes of, the bypass orifices, the
proportions of drilling fluid flowing through the fluid motor 5 and
around the fluid motor can be controlled. The proper sizes and
numbers of the orifices to meet the needs of a particular drilling
operation can be placed into the downhole pulsing-shock reach
extender 10 during inspection prior to use. In a preferred
embodiment shown, six bypass orifices can be placed into the top
sub 1.
The orifices 2, 3 will be subject to erosion or washout from
extended exposure to turbulent flow, but can be easily replaced
during cleaning and inspection of the tool. The adjustability of
the flow paths makes for adjustability of the tool response,
cycling rate, and amplitude for different flow rates and fluid
properties. The adjustability of the flow paths also ensure that
the fluid motor 5 can be run at flow rates within its optimum
window of operation, and not detrimental to the operating parts
within. The orifices 2, 3 are axially aligned with the tool housing
4 and fluid motor 5 so that they exhaust fluid parallel to the
other tool surfaces, lessening turbulence and the potential for
erosion.
The outer diameters of the tool housing 4, top sub 1, and bottom
sub 8 match that of the coiled tubing itself and the other
components of the workstring. In an embodiment appropriate for
standard 2.375-inch tubing in a 5.5-inch casing, an outer diameter
of 2.875 inches is appropriate. An embodiment of the downhole
pulsing-shock reach extender 10 is made of steel, as is known in
the art. The types of drilling fluid or mud used with
coiled-tubing, mud-motor operations will sufficiently cool and
lubricate a unit made of steel, and will suppress any potential
sparking. Other embodiments could be made from, or could have
components made from, non-sparking brass or from non-corroding
composite materials, if such qualities are needed.
Referring to FIG. 3 & FIG. 4, in use, the downhole
pulsing-shock reach extender 10 receives a flow of drilling fluid
under pressure into the top sub 1, where the center orifice 2 and
the bypass orifices 3 divert a portion of the flow to the perimeter
fluid channel surrounding the fluid motor 5, with the remaining
flow passing through the fluid motor. The drilling fluid passing
through the fluid motor 5 causes the fluid motor 5 to rotate. The
downhole end of the fluid motor 5 is connected to the foot-valve
top plate 6 such that the rotation of the fluid motor 5 rotates the
foot-valve top plate 6. As the foot-valve top plate 6 rotates in
relation to the fixed foot-valve bottom plate 7, the foot-valve top
plate 6 alternately covers and uncovers an opening through the
foot-valve bottom plate 7. When the opening through the foot-valve
bottom plate 7 is uncovered, the drilling fluid in the perimeter
fluid channel is allowed to flow into the downhole portion of the
bottom sub 8, where it combines with the flow through the fluid
motor 5, thereby increasing the pressure of the drilling fluid
exiting the bottom sub 8 and flowing to the rest of the workstring.
The rotating foot-valve top plate 6 then quickly covers the opening
through the foot-valve bottom plate 7, blocking the flow from the
perimeter fluid channel, while the flow through the fluid motor 5
continues, thereby decreasing the pressure of the fluid exiting the
bottom sub 8 and flowing to the rest of the workstring. This
continues in a cycle, and the pressure of the drilling fluid
flowing out of the bottom sub 8 and to the downhole components of
the workstring is pulsed or bumped, but never completely stopped,
since the flow through the fluid motor 5, foot-valve top plate 6,
and foot-valve bottom plate 7 is never stopped, and the other
components of the workstring are never completely starved of
mud.
The center orifice 2, bypass orifices 3, foot-valve top plate 6,
and foot-valve bottom plate 7 are removable and replaceable parts
so that they can be replaced when worn or eroded, and so that parts
having appropriately sized openings or open areas can be placed
into the downhole pulsing-shock reach extender 10 for optimal
performance of a given downhole operation. The top sub 1 and the
bottom sub 8 will also be subject to erosion, and can be replaced
easily and inexpensively. Different top subs 1, having different
numbers or sizes of openings for bypass orifices 3, can be provided
to accommodate particular requirements. These orifices, plates, and
subs are relatively small and inexpensive, and can be made up from
widely available components. The fluid motor 5 is the largest and
most expensive component of the downhole pulsing-shock reach
extender 10, but is available as a standard, existing part, and the
standard fluid motors are made for much more taxing applications,
and should not be subject to undue or accelerated wear in the
downhole pulsing-shock reach extender 10.
Many other changes and modifications can be made in the system and
method of the present invention without departing from the spirit
thereof. We therefore pray that our rights to the present invention
be limited only by the scope of the appended claims.
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